Published French Pat. No. 2 228 463 describes a device of this type for mounting on the bend in the grip or handle of the turbine in a dentist's drill, and comprises a fixing hook together with a protective wall. The wall pivots relative to the fixing hook about a geometrical axis which is parallel to the axis of the drill when in use. When drilling a tooth, it is necessary to be able to work on both of the free sides of a tooth, i.e. on the cheeck side and on the tongue side. It is also necessary to be able to work on the sides close to the adjacent teeth. In such a case, the known device abuts against the adjacent teeth. It has to be removed before working between teeth with the drill. It has even appeared that this known protector can be used on the tongue side of a tooth only for drilling the middle of said tongue side, since the width of the protective wall causes it to encounter the adjacent tooth well before the drill arrives in the proximity of said adjacent tooth.
A main object of the invention is to provide a protection device of the above-described type for protecting soft tissues, but which enables any point on the side of a tooth to be drilled from close proximity to a first adjacent tooth to close proximity to a second adjacent tooth at the opposite end of the tooth being drilled.